I thought I understood efficiency...

[kh54s10]

I have been hitting my numbers pretty consistently. I use a corona mill and have Beersmith set for 68% efficiency. I am usually within a point or two of target.

Today I did a wheat.

4 lbs white wheat malt
3 lbs Rahr 2 row
2 lbs Munich light
Orange peel
.75 oz coriander.


Beersmith says I got 72% mash efficiency but the estimated OG was 1.045 and I got only 1.031.

I am not worried as I was looking for a light summer ale. Just wondering why I got relatively good mash efficiency #'s and low OG?

 

[masskrug]

68% is pretty forgiving. I'm guessing the wheat threw it off. What temp did you mash? Ratio? WTH is Munich light? Light color?

 

[kh54s10]

68% is pretty forgiving. I'm guessing the wheat threw it off. What temp did you mash? Ratio? WTH is Munich light? Light color?

Mash temperature 148 degrees. Within 1 degree at start and 144 at 75 minutes.

Munich light? Weyermann Munich 1 I assume. The package/order was Light Munich. I don't remember where I bought it. 5.1 to 7.0 Lovibond on the Weyermann site.

IDK, I have used wheat in the past and the numbers were closer.

 

[dragonfire540]

Rice hulls. You may not have enough husks in there with all that wheat try adding hulls to get good flow and make sure you keep your sparge rate slow to get best extraction
I had similar issue till I started adding hulls and making my process consistent
Also make sure you know your volumes As efficiency calculations are only as good as your volumes just slight error in pre-boil volume will throw you off

 

[ajdelange]

I have been hitting my numbers pretty consistently. I use a corona mill and have Beersmith set for 68% efficiency. I am usually within a point or two of target.

Today I did a wheat.

4 lbs white wheat malt
3 lbs Rahr 2 row
2 lbs Munich light
Orange peel
.75 oz coriander.


Beersmith says I got 72% mash efficiency but the estimated OG was 1.045 and I got only 1.031.

I am not worried as I was looking for a light summer ale. Just wondering why I got relatively good mash efficiency #'s and low OG?

You used 9 lbs of grain. You don't say how much wort you prepared but assuming it was 5 gallons that would weigh

5*8.34*1.031 = 42.9927 lbs

1.031 SG is 7.8 Plato so you got 42.9927*7.8/100 = 3.35 lbs of extract. That, divided by the weight of the grain you used gives the efficiency.

100*(42.9927*7.8/100)/9 = 37.3%.

This is not, indeed, very good. Most home brewers attain something in the 60's. At 60%, for example, you'd have 5.4 pounds of extract in 5 gal of wort corresponding to 1.050 SG.

 

[stpug]

I have been hitting my numbers pretty consistently. I use a corona mill and have Beersmith set for 68% efficiency. I am usually within a point or two of target.

Today I did a wheat.

4 lbs white wheat malt
3 lbs Rahr 2 row
2 lbs Munich light
Orange peel
.75 oz coriander.


Beersmith says I got 72% mash efficiency but the estimated OG was 1.045 and I got only 1.031.

I am not worried as I was looking for a light summer ale. Just wondering why I got relatively good mash efficiency #'s and low OG?

9 lbs * 36 points per pound = 324 points at 100% efficiency
324 points / 5 gallons = 64.8 points/gallon at 100% efficiency
31 points achieved / 64.8 points possible = ~48% brewhouse efficiency

Not quite the same picture that AJ illustrated but still pretty poor efficiency. You definitely need to look into why you're missing out on 1/3 of the potential sugars from your grain because that's pretty significant.

On a different note: You say beersmith is set for 68% efficiency (this is usually brewhouse efficiency people look at in beersmith), and yet you report that beersmith reports you got 72% mash efficiency. Comparing the two is not overly useful with the exception that your brewhouse efficiency should never be higher than your mash efficiency, otherwise it's useless. BTW, 72% mash efficiency is also pretty poor, generally speaking. You should be able to get higher number from both efficiencies with some adjustments to your crush/process/system.

Now, give us some specifics about your system. The more information the better. MLT deadspace. How much wort you leave behind in your brew kettle. How much water you use during your brewing process and how much wort you get back out. Where you get your grain. How it gets crushed. A picture of the crush can sometimes be helpful. Etc. Anything else you can think of that I'm forgetting right now

 

[Gavin C]

Mash efficiency this low would point to a procedural error. Most likely a poor crush which was made even worse by the use of the smaller wheat kernels.

If you want to try to pin point where there may be room for improvement it may be worth measuring

1. conversion efficiency. How much sugars are in the mash tun after the mash/theoretical maximum sugars available (TMSA) You need to know the volume of water transferred into the mash tun and the gravity prior to lautering
   
2. Mash efficiency: How much sugars have been removed from the mash/TMSA. You need a preboil volume and gravity

If 1 is low (90+ percent is readily achievable with this grain bill) it points to either a poor crush or inaccurate temperature reading or non-optimal mash pH.

If 1 is good and 2 is low it points to an inadequate lautering process.

The brewhouse efficiency will of course be a bit lower as you lose some volumes to trub, hoses, plate chiller, hop absorption etc. Aside from the perceived bragging rights that many seem to equate the quest for high efficiency with, the numbers themselves can help highlight errors in the process. Crush, pH, sparging methods etc. There are lots of variables but each number will nail down the area that can be improved.

Better efficiency through refinement of the process leads to consistency as the pleasant byproduct. Consistency in brewing is something few could argue against. Many will not care one iota, but by the nature of the post I'm guessing you are not in that category.

I hope I have not confused things further. I am certainly no expert but am a bit of a fan of the number crunching game in brewing. A welcome outlet for my inner geek.

Note. For accuracy make sure the gravity is measured at the correct sample temp. I'm sure this is something you are already doing but if you are trying to nail down a system flaw it's very important to be as accurate as possible with both volume and gravity measures.

• Easy Volume measures
  
  
  [*]Correct Gravity Readings

 

[kh54s10]

OK, I use a corona mill, I ran it through twice. Crush was almost flower...
I have a 3 tier gravity system. HLT is a 10 gallon pot up top, MLT is a 10 gallon Rubbermaid cooler w/braid. BK is a 10 gallon kettle.
I did a batch sparge. I usually do a little more than half needed to get to preboil, then a second sparge to preboil amount. This time I did a single sparge. There is almost nothing left in the tun when drained.
I used a couple hand fulls of rice hulls and had no problems draining.
I used a refractometer for the gravity measurements. It is the automatic temperature kind. I also waited long enough that the sample would have cooled.

I have made wheat beers before and had much closer to predicted results.

I have to look at the types of efficiency measurements more. But I am usually within a couple points OG this was one of the farthest off I have had.
Good news it that I should be able to drink a lot of it at one sitting.

I don't think I made any measurement mistakes or left anything out. I use a thermapen and think it is spot on. Mash temp started good, dropped about as usual.

 

[Gavin C]

That's a puzzler for sure.

Were the rice hulls presoaked. If not then they will soak up some of the sweet wort reducing the mash efficiency. I don't think that alone would account for your numbers.

A Thermapen for temp readings mean you can probably discount any errors there. You can always double check its calibration in a glass of crushed ice/water mix to be sure.

An overly fine crush may have led to some dough balls in a thick mash reducing the conversion and mash efficiencies.

A braid. I know many swear by them. Likewise many posters deride them as ineffective and promoting channelling. Something to look at maybe.

Just some thoughts. I'm not a three vessel brewer so I don't speak with any level of practical knowledge I'm afraid. Many of these points may be redundant or way off base.

 

[spenghali]

When did you take your sample for gravity and where was it pulled from? Your wort might not have been homogeneous...

 

[ajdelange]

I used a refractometer for the gravity measurements. It is the automatic temperature kind. I also waited long enough that the sample would have cooled.

That may very well be your problem. Refractometers, especially ATC equipped ones if the temperature of the sample isn't carefully controlled, can't be relied on for gravity measurement. They are often quite close but on occasion can be off by a couple of Bx. I grant you, 3 Bx is quite a lot.

Please understand that I am not saying that use of refractometer is your problem. Just that it could be. Perhaps the wort was indeed of normal gravity.

 

[IslandLizard]

[...] An overly fine crush may have led to some dough balls in a thick mash reducing the conversion and mash efficiencies. [...]

Although that's true, if you didn't change anything on the milling, chances are that your wheat wasn't crushed well at all. Wheat kernels are much smaller and harder than barley. A larger percentage may have passed through whole. If you still can, check your spent grains for large grain bits.

Although rice hulls will soak up some wort, it is quite minimal, maybe an ounce or two.

 

[kh54s10]

That's a puzzler for sure.

Were the rice hulls presoaked. If not then they will soak up some of the sweet wort reducing the mash efficiency. I don't think that alone would account for your numbers.

I did not soak the rice hulls and never have.

A Thermapen for temp readings mean you can probably discount any errors there. You can always double check its calibration in a glass of crushed ice/water mix to be sure.

I haven't checked it recently but have in the past, it was accurate.

An overly fine crush may have led to some dough balls in a thick mash reducing the conversion and mash efficiencies.

There were no dough balls. Because of the wheat I checked this carefully.

A braid. I know many swear by them. Likewise many posters deride them as ineffective and promoting channelling. Something to look at maybe.

Channeling should not be a problem since I batch sparge.

Just some thoughts. I'm not a three vessel brewer so I don't speak with any level of practical knowledge I'm afraid. Many of these points may be redundant or way off base.

When did you take your sample for gravity and where was it pulled from? Your wort might not have been homogeneous...

I took the measurement, it was low so I stirred the wort well and still got the low numbers.

That may very well be your problem. Refractometers, especially ATC equipped ones if the temperature of the sample isn't carefully controlled, can't be relied on for gravity measurement. They are often quite close but on occasion can be of by a couple of Bx. I grant you, 3 Bx is quite a lot.

Please understand that I am not saying that use of refractometer is your problem. Just that it could be. Perhaps the wort was indeed of normal gravity.

I have used the refractometer for a couple of years now and get reliable readings with it. I believe the #'s.

Although that's true, if you didn't change anything on the milling, chances are that your wheat wasn't crushed well at all. Wheat kernels are much smaller and harder than barley. A larger percentage may have passed through whole. If you still can, check your spent grains for large grain bits.

Since there was wheat, I double milled and checked it thoroughly before the brew. That is not the source of the inefficiency.

Although rice hulls will soak up some wort, it is quite minimal, maybe an ounce or two.

IDK??? I guess I am just going to enjoy a Summer Wheat that is more session-able than originally intended.


Looking again at Beersmith
Measured Mash efficiency = 72.5
Measured efficiency = 56.5

Again, there was nothing really different from previous brews and I usually hit my gravities very closely. ????

 

[doug293cz]

I can't see anything obvious that would cause efficiency that low. Is there any possibility that you got some unmalted grain by mistake?

Brew on

 

[FatDragon]

Looking again at Beersmith
Measured Mash efficiency = 72.5
Measured efficiency = 56.5

Again, there was nothing really different from previous brews and I usually hit my gravities very closely. ????

Not sure why you got such low efficiency - the above posters have already addressed some possible reasons - but your Beersmith numbers are the result of a data entry error. I've got my Beersmith set to metric units, but recreating the grainbill and OG of that brew within a few grams/milliliters here and there, I got an estimated OG of 1.046 (at 68% efficiency) and an actual efficiency in the low 40's. I then popped over to the "Mash" tab and looked down at the "Mash Efficiency" readout - lo and behold, 73.4%! How could that be? Because while I changed the final volume and OG numbers on the "Design" tab, I didn't adjust any of the "Volume and Gravity in Boiler" variables on the "Mash" tab. Beersmith's calculating your mash efficiency based on the default numbers in the "Meas Pre-Boil Vol" and "Meas Pre-Boil Gravity" fields, rather than whatever your actual pre-boil volume and gravity were, so the mash efficiency calculations have nothing to do with your actual brew. If you took a pre-boil gravity sample and have a good estimate of your pre-boil volume, pop those numbers in there and your efficiency reading will miraculously (and maybe a bit depressingly) plummet to reflect what actually happened with this beer.

 

[kh54s10]

Not sure why you got such low efficiency - the above posters have already addressed some possible reasons - but your Beersmith numbers are the result of a data entry error. I've got my Beersmith set to metric units, but recreating the grainbill and OG of that brew within a few grams/milliliters here and there, I got an estimated OG of 1.046 (at 68% efficiency) and an actual efficiency in the low 40's. I then popped over to the "Mash" tab and looked down at the "Mash Efficiency" readout - lo and behold, 73.4%! How could that be? Because while I changed the final volume and OG numbers on the "Design" tab, I didn't adjust any of the "Volume and Gravity in Boiler" variables on the "Mash" tab. Beersmith's calculating your mash efficiency based on the default numbers in the "Meas Pre-Boil Vol" and "Meas Pre-Boil Gravity" fields, rather than whatever your actual pre-boil volume and gravity were, so the mash efficiency calculations have nothing to do with your actual brew. If you took a pre-boil gravity sample and have a good estimate of your pre-boil volume, pop those numbers in there and your efficiency reading will miraculously (and maybe a bit depressingly) plummet to reflect what actually happened with this beer.

I have never changed the numbers there and never missed by as much.

I just changed the numbers and it shows estimated mash eff 69.4
and measured mash eff 64.7 the measured efficiency on the design page still says 56.5 So that made changed it a little.

Now I wonder why, if I never changed the numbers on the mash page before, why do I usually get the proper pre-boil gravity and OG??

 

[ajdelange]

I have used the refractometer for a couple of years now and get reliable readings with it. I believe the #'s.


Perhaps you do but you shouldn't unless you have checked them against a hydrometer in which case I don't see any point in using the refractometer. Refractometers really do not belong in the brewery unless they are properly calibrated for the type of beer being brewed against a more reliable instrument.

 

[leesmith]

Any changes to your system.?
I do ebiab and just changed to using a sprayer head along with a basket to hold the bag and grains.
My efficiency went way down, but I also learned the difference between mash efficiency and brewhouse....just need to adjust my brewhouse efficiency to lower my mash one from 90 something to 75 or so. Basically a little more malt. I'll see if this works during the next brew. If not I'll switch back to my old way.

Oh and my refractometer can be all over the place...I keep distilled water on hand to calibrate during the brew day.

 

[ajdelange]

Distilled water will set the 0 point but cannot compensate for slope changes which are evidently associated with variability in the sugar spectrum.

 

[leesmith]

Yeah
I'm beginning to get annoyed with my refractometer to the point of using my hydrometer. They do match roughly which is good enough for me. I worry about the drastic swings (a whole brix point) of the refractometer and not being aware of it....that's where things can get really messed up.

Anyways...one other thing I've wondered and haven't gotten a clear answer: could the age of the grain cause the efficiency to be off?

 

[ajdelange]

If malt goes 'slack' (takes up a lot of water) then clearly it contains less potential extract per pound than low moisture content malt. This might account for a few percent decrease in efficiency but not 10's of percent.

 

[Owly055]

There are numerous reasons your OG might be low.......... But no reason why Beersmith should say your efficiency was high when projected OG is low...... that simply does not compute at all. Your OG is what determines your mash efficiency... period.


H.W.

 

[FatDragon]

I have never changed the numbers there and never missed by as much.

I just changed the numbers and it shows estimated mash eff 69.4
and measured mash eff 64.7 the measured efficiency on the design page still says 56.5 So that made changed it a little.

Now I wonder why, if I never changed the numbers on the mash page before, why do I usually get the proper pre-boil gravity and OG??

Beersmith calculates Mash Efficiency and Measured Efficiency from completely different user-entered variables - Mash Efficiency comes from Pre-Boil Gravity and Volume, where Measured Efficiency comes from OG and Measured Batch Size - both measured after the boil. In real life, mash efficiency has a direct impact on what Beersmith calls "Measured" efficiency. In Beersmith, the numbers don't meet one another, so you could get vastly disparate numbers there if you put in the wrong measurements (for example, entering your post-boil OG in the pre-boil OG field).

If I were staring over your shoulder and knew all of your brewday numbers (including some which you may not have measured), I could probably tell you where you messed up the data entry and caused Beersmith to give you some false readouts, but all I can tell you with certainty is that any disparity between your actual efficiency and what Beersmith is saying about your efficiency is a data entry issue - maybe you put the wrong numbers in certain fields, maybe you don't have the right numbers for certain fields, maybe you didn't enter anything in certain fields and Beersmith is calculating from its default numbers. I recommend you dig deeper into how to use Beersmith to get a more accurate understanding of your brew, or just ignore all that auxillary stuff and understand that it might not reflect your real-life numbers. Either way, while it's important to understand your software if you're relying on it for understanding and tweaking your brewing process, the first thing to do is diagnose why you got such low efficiency in the first place and work on fixing that.

 

[kh54s10]

Either way, while it's important to understand your software if you're relying on it for understanding and tweaking your brewing process, the first thing to do is diagnose why you got such low efficiency in the first place and work on fixing that.

As I have said, there was nothing that I can determine that I did differently on this batch. I may never know why I missed my OG by so much.

 

[kh54s10]

I can't see anything obvious that would cause efficiency that low. Is there any possibility that you got some unmalted grain by mistake?

Brew on

I doubt there is any chance it was unmalted. http://www.farmhousebrewingsupply.com/white-wheat-cmc-1-lb/

I have used the refractometer for a couple of years now and get reliable readings with it. I believe the #'s.


Perhaps you do but you shouldn't unless you have checked them against a hydrometer in which case I don't see any point in using the refractometer. Refractometers really do not belong in the brewery unless they are properly calibrated for the type of beer being brewed against a more reliable instrument.

I have not checked directly against a hydrometer sample and probably will next brew day. But then again I am usually within a point or two of what I expect, this time it was way off. I don't think the refractometer is the issue.

Any changes to your system.?
I do ebiab and just changed to using a sprayer head along with a basket to hold the bag and grains.
My efficiency went way down, but I also learned the difference between mash efficiency and brewhouse....just need to adjust my brewhouse efficiency to lower my mash one from 90 something to 75 or so. Basically a little more malt. I'll see if this works during the next brew. If not I'll switch back to my old way.

Oh and my refractometer can be all over the place...I keep distilled water on hand to calibrate during the brew day.

I checked the calibration several times during the day. And no other changes.

Distilled water will set the 0 point but cannot compensate for slope changes which are evidently associated with variability in the sugar spectrum.

This is true but again, I have not often been off by more than a couple points. This time it was way off.

I think I have learned a little about the efficiency numbers and calculations, but still don't have a clue why this brew went awry... I plan to brew tomorrow so I'll soon know if I will have a recurring problem. Now to decide what to brew?!!?

 

[FatDragon]

As I have said, there was nothing that I can determine that I did differently on this batch. I may never know why I missed my OG by so much.

Sure. My last sentence there was as much an aside as anything: the question you posed in the OP seemed to be more about Beersmith than your actual efficiency, so that's what I've addressed primarily.

At the same time, barring a measurement error that could be user- or equipment-based, something was different this time around. Maybe your grains were really old and had somehow lost a great deal of their potential gravity. Maybe your scale is normally set to kg and you accidentally had it set to pounds. Maybe your mash temps were way off due to a thermometer issue. Maybe you straight-up forgot one of your grains. It's probably not one of those, but if your gravity and volume measurements are all correct, your process didn't change, and your efficiency dropped by over 20%, something was different. Extraction can fluctuate by a couple points across otherwise-identical brewdays, but nowhere close to this much.

 

[kh54s10]

Sure. My last sentence there was as much an aside as anything: the question you posed in the OP seemed to be more about Beersmith than your actual efficiency, so that's what I've addressed primarily.

At the same time, barring a measurement error that could be user- or equipment-based, something was different this time around. Maybe your grains were really old and had somehow lost a great deal of their potential gravity. Maybe your scale is normally set to kg and you accidentally had it set to pounds. Maybe your mash temps were way off due to a thermometer issue. Maybe you straight-up forgot one of your grains. It's probably not one of those, but if your gravity and volume measurements are all correct, your process didn't change, and your efficiency dropped by over 20%, something was different. Extraction can fluctuate by a couple points across otherwise-identical brewdays, but nowhere close to this much.

I agree.

My first thought was that I didn't understand the efficiencies in Beersmith. I wasn't totally off base and I have learned a little more.

I don't believe I made any measurement errors but must have, somewhere.

I guess I will never figure this one out?!?!?

 

[stpug]

Recipe:
......4 lbs white wheat malt
......3 lbs Rahr 2 row
......2 lbs Weyermann Munich I
......rice hulls

......Mash temperature 148 degrees
......batch sparge: single sparge this time (sounds like no sparge though)

Equipment Setup:
......HLT is a 10 gallon pot
......MLT is a 10 gallon Rubbermaid cooler w/braid (minimal loss)
......BK is a 10 gallon kettle

Beersmith Data:
......estimated OG was 1.045
......measured OG was 1.031

......Beersmith says:
......Measured Mash efficiency = 72.5
......Measured BH efficiency = 56.5

......Changed the numbers and Beersmith shows:
......Estimated Mash efficiency = 69.4
......Measured Mash efficiency = 64.7
......Measured BH efficiency = 56.5

Questions:
......Just wondering why I got relatively good mash efficiency #'s and low OG? I may never know why I missed my OG by so much

To answer your question above:
You did not get good mash efficiency. Mash efficiency should almost always be approaching 90% as this means that you're getting most of the potential sugars out of the grain into your brewpot - how you lose them afterwards is up to you. Your low OG (i.e. brewhouse efficiency) is another indicator that your mash efficiency was very poor, as it directly depends on mash efficiency. Brewhouse efficiency is always <= your mash efficiency.

You are correct that you may never know why you missed the OG (i.e. missed getting the potential sugars from the grain) by so much. It's pretty much a guessing game at this point.

My two guesses are:
1) Some pounds of grain were missing from your grist
2) Some pounds of grain were never milled
3) The milling of the entire grist was very poor
4) The devil came up and slurped them out of your pot while you were not looking

Below is an example beersmith file of the beer your brewed based on my understanding from this thread. I wonder how much yours differs from this one.
View attachment WheatExample.bsmx

 

[ajdelange]

The possibilities are:

1)The amounts of grain that actually made it into the mash tun were substantially less than reported (weighing error - check scale)
2)The grind was terrible - check mill (presumably it's still set the same)
3)The gravity of the mash was measured in error (use hydrometer)

Even if he'd had only 60% overall efficiency he should have gotten about 1.050 which, with 75% attenuation, would give a final AE of about 1.012. If indeed the realized OE was only 1.031 the final AE would, assuming equal apparent attenuation, be about 1.008. Some time has passed. What's the gravity now and/or what does a force test show? If 1) or 2) above pertains the beer will be a small beer indeed. If it's 3), the beer may be fine.

 

[Owly055]

I use Brewer's Friend.... a simpler program that doesn't confuse the issue of efficiency. It has only one efficiency, and that's brewhouse efficiency which is everything rolled into one as far as I can tell.

My take on efficiency is that the only reason for having two efficiency ratings is the addition of fermentables to the boil. I'm talking about things like corn sugar, honey, etc, which do not have to be converted to ferment.

The ONLY efficiency rating that matters is conversion efficiency (mash efficiency), it's the only one you have control over. Nothing after the mash changes that, but if you take a gravity post boil, it will include the sugars you mashed and the ones you added to the boil. So if you add a lot of sugars to the boil, those sugars are 100% efficient.... they are already converted to sugar. That masks your mash efficiency unless you account for it mathematically. Your measured efficiency should NEVER be less than your mash efficiency if your liquid volumes are correct and your readings right.


H.W.

 

[Gavin C]

I use Brewer's Friend.... a simpler program that doesn't confuse the issue of efficiency. It has only one efficiency, and that's brewhouse efficiency which is everything rolled into one as far as I can tell.

My take on efficiency is that the only reason for having two efficiency ratings is the addition of fermentables to the boil. I'm talking about things like corn sugar, honey, etc, which do not have to be converted to ferment.

The ONLY efficiency rating that matters is conversion efficiency (mash efficiency), it's the only one you have control over. Nothing after the mash changes that, but if you take a gravity post boil, it will include the sugars you mashed and the ones you added to the boil. So if you add a lot of sugars to the boil, those sugars are 100% efficient.... they are already converted to sugar. That masks your mash efficiency unless you account for it mathematically. Your measured efficiency should NEVER be less than your mash efficiency if your liquid volumes are correct and your readings right.


H.W.

I thought conversion efficiency related to what percentages of starch converted to sugars in the mash.

The mash efficiency relates to how much sugars enter the boil kettle and unlike conversion efficiency is subject to additional losses including grain absorption and mash tun deadspace (if any). Is this semantics or am I way off base here.

In my experience measured BH efficiency is ALWAYS less than mash efficiency as I lose some sugars via volume losses to hop absorption, kettle true and plate chiller/hoses. (about 0.25 G)

Perhaps I am misunderstanding you. Most likely I am.

 

[Owly055]

I thought conversion efficiency related to what percentages of starch converted to sugars in the mash.

The mash efficiency relates to how much sugars enter the boil kettle and unlike conversion efficiency is subject to additional losses including grain absorption and mash tun deadspace (if any). Is this semantics or am I way off base here.

In my experience measured BH efficiency is ALWAYS less than mash efficiency as I lose some sugars via volume losses to hop absorption, kettle true and plate chiller/hoses. (about 0.25 G)

Perhaps I am misunderstanding you. Most likely I am.

I'm using conversion efficiency and mash efficiency interchangeably......... conversion efficiency is a useless figure, and one you can't really measure.

Brewhouse efficiency is a number that could be calculated in many ways.... "lies, damn like, and statistics". I recently put 2.5 gallons of wort in a fermenter, measuring the OG and using the BF program to calculate it brewhouse efficiency based on 2.5 gallons. The way I always do it. Now, I probably should factor in the quart or so I lose to trub in the fermenter (10%). The number was 93%... the highest I've hit so far......... That number really represents mash efficiency, as absorption from the small amount of pellet hops is trivial........ The real question is "does it matter".......... and it doesn't unless we are having a pissing match over who gets the highest efficiency, which would be silly. I monitor my efficiency this way every time, and use the figure to see how I'm doing with my mash. I have no way of knowing how Brewer's Friend handles the input..... weather trub loss is calculated in, etc...........nor do I really care.

Just looked up Brewhouse Efficiency at Brewer's Friend:

Brew House Efficiency - An all inclusive measure of efficiency, which counts all losses to the fermentor. This can be thought of as 'to the fermentor' efficiency. Hops absorption factors into this, and is reduced on the same equipment by ~1% in super hoppy beers.

H.W.

 

[Gavin C]

Fair enough Owly.

I would take a differing approach to the numbers but each to their own i suppose. I would disagree with you on conversion efficiency and mash efficiency equivalence even if the former is difficult but not impossible to measure.

I view the software as a tool like any other. It serves a purpose. That purpose is determined by the brewer. Putting aside their usefulness in formulating recipes, I think these tools become particularly useful when trying to find a process error or in the refinement of an existing brewing process.

I'm sure the OP will have his own take on the software and use it accordingly.

Thanks for answering my query BTW

 

[CGish]

I have been hitting my numbers pretty consistently. I use a corona mill and have Beersmith set for 68% efficiency. I am usually within a point or two of target.

Today I did a wheat.

4 lbs white wheat malt
3 lbs Rahr 2 row
2 lbs Munich light
Orange peel
.75 oz coriander.


Beersmith says I got 72% mash efficiency but the estimated OG was 1.045 and I got only 1.031.

I am not worried as I was looking for a light summer ale. Just wondering why I got relatively good mash efficiency #'s and low OG?

I usually hit 68% with a single pass through my corona mill. However, a few weeks ago I brewed a wheat beer and did not check to see if conversion was complete. It was a 90 minute mash, so I did not double check. I wound up with 40% efficiency on that brew. Three pounds of DME got me back in the ballpark, but it still came out light. I was set for a second brew that day with a similar grist. The second time I checked for conversion and it took almost 2 hours. At 90 minutes, the iodine still turned the mash black. Around 1 hour 45 minutes the color started to lighten and at 2 hours it was finally done. The second mash's numbers were right where they should be, coming in at 1.052 against the projected 1.053.

I have brew twice since then and had normal (30 - 45 minute) conversion times. It seems the bulk wheat malt I have is a slow converter.

Is it possible you just had a slow conversion and stopped the mash to early?

Cody

 

[ajdelange]

There is only one efficiency that matters and that is the effective extract delivered to the kegs on the loading dock divided by the pounds of grain that were used to produce those kegs. It accounts for
1)Slackness in the malt
2)Extract hung up in the grain bed at sparge
3)Water losses/gains due to evaporation/dilution (kettle, fermenter)
4)Extract losses due to boilovers
5)Extract hung up in the chiller or the transfer lines or the fermenter or anywhere else or spilled on the floor or retained in the yeast cake.

One can, of course, calculate the efficiency at various stages in the process. For example, if a brewer has 65% efficiency at the kettle and the maltster has told him that the FGHWE as is was 81% for a particular malt he knows he has lost 16% as unconvertible starch, husks, acrospires and equipment shortcomings. If he is used to getting 70% from this grain he knows he has lost 5% more than he should and seeks the source of the problem. If he gets 60% in the keg he knows he has lost 5% extract in the fermenter and filling process. And so on.

 

[doug293cz]

Here are the definitions of efficiency that seem most intuitive to me:

Conversion Efficiency: The percentage of grain sugar potential that is actually obtained in the mash. Conversion efficiency is affected by mash temp & time, mash pH, grain particle size, diastatic power, mash thickness, agitation, etc. Conversion efficiencies in excess of 98% are readily obtainable.

Lauter Efficiency: The percentage of the sugar in the mash that makes it into the boil kettle. Lauter efficiency is calculated as: (Mash Efficiency) / (Conversion Efficiency). It is affected by things like grain absorption and undrainable wort volume (MLT dead space.)

Mash Efficiency: The percentage of grain sugar potential that actually makes it into the boil kettle. Mash_Efficiency = Conversion_Efficiency * Lauter Efficiency

Brewhouse Efficiency: The percentage of the grain sugar potential that actually makes it into the fermenter. The difference between brewhouse efficiency and mash efficiency is caused by hop absorption, volume held in plumbing, trub volume withheld from fermenter, spills, etc.

By knowing each of your efficiencies, you can know where to look if your overall (brewhouse) efficiency is falling short.

To calculate any efficiency, we need to know the potential points of the starting grain bill. This is the sum of the grain weight * grain potential points/unit wt.

Typical pale 2 row has a potential SG of 1.036 for 1 lb of grain in 1 gal of wort, or 36 potential points/lb

10 lbs of two row would then have 10 * 36 = 360 potential points​

We also need to know the actual points in any volume of wort. Actual points is given by the volume times the points/gal, and points/gal is (SG - 1) * 1000.

Mash efficiency is easy to calculate; it is:

[(Pre-boil Volume) * (1 - Pre-boil SG) *1000)] / (Potential Grain Points)
​

With volume and SG corrected to room temp.

So if from my 10 lbs of 2 row, I obtain 6.75 gal of 1.049 SG wort @ 150°F in my boil kettle (equivalent to 6.5 gal @ 70°F), then I have obtained:

6.5 * (1.049 - 1) * 1000 = 318.5 points
​

and my mash efficiency is:

318.5 / 360 = 0.8847 => 88.5% mash efficiency
​

Brewhouse efficiency is calculated as:

[(Volume in fermenter) * (OG - 1) * 1000] / (Potential Grain Points)
​

So if I net 5.25 gal of 1.058 wort to the fermenter, my brewhouse efficiency is:

5.25 * 58 / 360 = 0.8458 => 84.6%
​

The calculations for conversion efficiency are a little trickier, as you have to know how much sugar is in a wort with a given SG. To start we need to calculate the weight of the sugar that is equivalent to the potential gravity points. The easiest way to do this is to assume a wort volume in the mash that is near the expected total wort volume. So, let's assume we have 10 gal that contain the 360 total points, which would give us an SG of 1.036. Now we convert the SG to Plato so that we know what percentage by weight of the wort is sugar, and the balance will be water.

10 gal of 1.036 wort will weigh 10 lbs * 1.036 * 8.3290 lbs/gal = 86.28844 lbs
1.036 = 9.00 Plato = 9.00 wt% sugar (I use Beersmith calculator)
Wt of sugar is 0.0900 * 86.28844 = 7.7659596 lbs
Wt of water is 0.9100 * 86.28844 = 78.5224804 lbs
Vol of water is 78.5224804 lbs / 8.3290 lbs/gal = 9.4276 gal
​

Now let's say we actually mashed with 4 gal of water. We then have:

Wt of strike water is 4.0 gal * 8.3290 lbs/gal = 33.316 lbs
Potential sugar wt = 7.7659596 lbs
Max SG = 7.7659596 lbs / (7.7659596 lbs + 33.316 lbs) = 0.1890 => 18.90 Plato
18.90 Plato = 1.079 SG of mash wort with 100% conversion
​

So, the maximum possible wort SG (in the MLT) with 10 lbs of 2 row and 4 gal of strike water is 1.079.

Now, I can measure the SG in my MLT, but I can't measure the actual wort volume, so how do I calculate how much sugar is in the wort? Let's say I measure an SG of 1.078, which is equivalent to 18.76 Plato.

Let X = the lbs of sugar created in the wort
Then 0.1876 = X / (X + 33.316) -- yes, it's algebra, which you thought you wouldn't need in real life.
X = 0.1876 * (X + 33.316)
X * (1 - 0.1876) = 6.2500816
X = 6.2500816 / (1 - 0.1876) = 7.69335499754 lbs sugar in wort in MLT
​

My Conversion efficiency is then (actual sugar in mash) / (potential sugar in mash):

Conversion efficiency = 7.69335499754 / 7.7659596 = 0.990650916796 =>99.07%
​

Finally, I can get to my lauter efficiency = (mash efficiency) / (conversion efficiency):

0.8847 / 0.99065 = 0.893050017665 => 89.31%
​

Whew

Brew on

 

[ajdelange]

It isn't really that tricky to figure out how much sugar is in a volume of wort at a given SG. The first step, of course, is to correct the wort volume to 20 °C. The next step is to compute the weight of the given volume which is simply W = SG*V*dens_water. Then find the amount of sugar in the water by multiplying by the Plato value
°P = -616.868+1111.14*SG-630.272*SG*SG+135.997*SG*SG*SG
divided by 100. For example a liter of 1.036 wort weighs 1.036*998.203 = 1034.14 grams. The w/w strength of 1.036 wort is 9.02446% so the grams of sugar are 1.036*998.203*9.02446/100 = 93.3254 grams. The rest is water.

The only thing that is at all tricky is when you put x grams of sugar into a container and add water until you have y liters and want to know what the SG is. So lets work the problem in reverse and say we put 93.3254 grams into a flask and made up to one liter. What's the SG. Well we know the weight of the sugar is
93.3254 = 1L*SG*dens_water*(-616.868+1111.14*SG-630.272*SG*SG+135.997*SG*SG*SG)/100
and we have to solve that for SG. This is actually very easy to do using the Excel Solver. It produces 1.036000024 as the solution.

Given the ASBC polynomial

°P = -616.868+1111.14*SG-630.272*SG*SG+135.997*SG*SG*SG

and modern laptops there is no reason home brewers should be worrying this potential points.... business any more than professional brewers do.

 

[doug293cz]

It isn't really that tricky to figure out how much sugar is in a volume of wort at a given SG.

"Tricky" is a relative term. Compared to the simple points computations, this problem is a little more complex. However, compared to integral equations, it's trivial. I just wanted to give readers who hadn't reached the tl:dr threshold a heads up that they needed to pay closer attention.

The first step, of course, is to correct the wort volume to 20 °C. The next step is to compute the weight of the given volume which is simply W = SG*V*dens_water. Then find the amount of sugar in the water by multiplying by the Plato value
°P = -616.868+1111.14*SG-630.272*SG*SG+135.997*SG*SG*SG
divided by 100. For example a liter of 1.036 wort weighs 1.036*998.203 = 1034.14 grams. The w/w strength of 1.036 wort is 9.02446% so the grams of sugar are 1.036*998.203*9.02446/100 = 93.3254 grams. The rest is water.

Isn't this pretty much what I did, except for using 21.1°C for a reference instead of 20°C (or did I miss something subtle)? But, I don't work with the ASBC polynomial on a regular basis, so I punted and used the Beersmith converter instead. I will be very disappointed if Brad does not use the ASBC poly. Thanks for including the actual polynomial. I will add it to my tool belt. Do you know offhand what the valid ranges of SG are for the poly?

The only thing that is at all tricky is when you put x grams of sugar into a container and add water until you have y liters and want to know what the SG is. So lets work the problem in reverse and say we put 93.3254 grams into a flask and made up to one liter. What's the SG. Well we know the weight of the sugar is
93.3254 = 1L*SG*dens_water*(-616.868+1111.14*SG-630.272*SG*SG+135.997*SG*SG*SG)/100
and we have to solve that for SG. This is actually very easy to do using the Excel Solver. It produces 1.036000024 as the solution.

This isn't really a problem you need to solve to understand your mash. You know how much potential sugar you put in, and how much water you put in, but you have no idea what the actual liquid volume is in the wort, and no way to measure it easily. I gave one way to calculate it (assuming all potential sugar has been converted, and the concentrations throughout the liquid have come to equilibrium.)

Given the ASBC polynomial

°P = -616.868+1111.14*SG-630.272*SG*SG+135.997*SG*SG*SG

and modern laptops there is no reason home brewers should be worrying this potential points.... business any more than professional brewers do.

So true. But then given the sensitivity of the calculations to small measurement errors, and the fact that most brewers don't have access to malt data for each lot that they use, how important is complete rigor in the calculations? The intent of my post was to help people understand how the different efficiencies are calculated, not how to make these measurements/calculations in a QC lab.

Brew on

 

[ajdelange]

"Tricky" is a relative term. Compared to the simple points computations, this problem is a little more complex. However, compared to integral equations, it's trivial. I just wanted to give readers who hadn't reached the tl:dr threshold a heads up that they needed to pay closer attention.

I don't know what tl:dr means but I agree that this is all very simple stuff, even if you stick to the robust solution methods. That's why I don't see any point in using the ppppg method. It makes the assumption that volume expansion is linear and it isn't. Granted that the deviation from linearity is so small that it doesn't make much practical difference. Given that you are likely to do your planning on a spreadsheet rather than a yellow legal pad I don't see any reason to accept even the small inaccuracy that comes from the approximate method.

Isn't this pretty much what I did, except for using 21.1°C for a reference instead of 20°C (or did I miss something subtle)? But, I don't work with the ASBC polynomial on a regular basis, so I punted and used the Beersmith converter instead.

I hope so or you wouldn't even get an approximately correct answer.

I will be very disappointed if Brad does not use the ASBC poly. Thanks for including the actual polynomial.

If he converts 1.036 SG to 9 °P he doesn't.

. Do you know offhand what the valid ranges of SG are for the poly?

It spans the Plato table which goes up to 1.083 20/20 SG (20.007 °P ). Above that you can use

°P = -584.6957 + 1038.2666*SG -577.9848*SG*SG + 124.5209*SG*SG*SG

which is a best fit to sucrose data in the CRC handbook (corrected to 20/20) and is continuous both in ordinate and slope with the ASBC polynomial at 1.083. Or you can use the ICUMSA polynomial which is a relative mess but is good for very concentrated solutions and at any temperature.

This isn't really a problem you need to solve to understand your mash.

It's probably the one I 'solve' the most as it's the one used to plan a brew. If I use x kg of malt that I know, from experience, has a certain percentage yield to prepare y liters of beer then I need to know how many grams of extract will be in each liter of that beer in order to calculate its °P and SG. Again, this is done in a spreadsheet so you can conveniently see the effect of swapping a kg of malt A for a kg of malt B and as you want the answers (°P and SG) to change as soon as you change a malt weight field you can't use the Solver. The answer is to precompute solutions over a reasonable range of °P and fit another polynomial to that data. The extract is

E = 0.0061289 + 0.99464*P + 0.0042888*P*P kg/hL

This is a very good fit with error about 5 mg/hL at the ends of the Plato table range and more like 2 - 3 mg/hL in the middle and, of course, is trivially solved for P if E is given without iteration (the Solver uses iterative techniques).

...most brewers don't have access to malt data for each lot that they use,

But they blindly accept tables in old brewing books that say that a malt of a given color produces a certain number of points per pound per gallon which is the same thing except less reliable than the maltsters data sheet.

....how important is complete rigor in the calculations?

Depends on what you are trying to do. The point is that with a modern spreadsheet there is no reason to accept the inaccuracies that come with the old 'points' system of calculation so why accept them? Proper calculations are just not that difficult and if the brewer's focus is on extract (rather than points) he'll have a better understanding of the science underlying the process.

The intent of my post was to help people understand how the different efficiencies are calculated, not how to make these measurements/calculations in a QC lab.

They would be better served by focusing their attention of extract levels at each stage of the process.
Yes, yes, I know that better is the enemy of good enough but I just hate that concept so I guess philosophy comes into it too.

 

[ajdelange]

Caveat - Brewing Science stuff

I will be very disappointed if Brad does not use the ASBC poly.

I got sort of intrigued here as to what he might actually be doing.

Using this as an example:

18.90 Plato = 1.079 SG of mash wort with 100% conversion

The estimated equivalent SG inverting the ASBC polynomial is 1.078093
The estimated equivalent SG interpolating into the Plato table 1.078095*
The estimated equivalent SG inverting the Lincoln equation is 1.078107
The estimated equivalent SG inverting ICUMSA polynomial is 1.078140

*Looks as if the polynomial represents the table pretty well

Those are the four methods a professional brewer would use to convert Plato to SG and all give 1.0781 to 4 decimal places so apparantly none of these is being used. I've shown 6 decimal places as that is the precision available from the best instruments, the precision of the Plato table, and the level of precision of interest to brewing scientists (recall that this is the Brewing Science thread).

I suppose it is also worth mentioning that these specific gravities are apparent (in air) and 20/20. Perhaps this calculator is calculating something else. The true specfic gravity for 18.9 °P is (ICUMSA) 1.078046 so that's not what has been done. Perhaps he is using 10/10°C as the reference temperature. That would give 1.07900 as the apparent specific gravity (ICUMSA).

All of this is, for practical purposes, moot but it is definitely of interest to brewing scientists and any one on this thread is presumably a brewing scientist (though an amateur one) and potentially interested. If not, don't read it.